l’lumia (1991), 12, 263-267 Cyclic AMP as a Second Messenger for Prorenin Release from Human Decidual Cells A. M. POISNER”~“, K. THRAILKILL$ R. POISNER” & S. HANDWERGERbpd a Department of Pharmacology, University of Kansas Medicul Center, Kansas City, Kansas 6610.? and ’ Department of Pediatrics, Duke University Medical Center, Durham, North Carolina 2 7710, US4 ‘ To whom correspondence should be addressed d Present address: University of Cincinnati/Children’s Hospital Medical Center, Department of Pediatrics, Elland and Bethesdu Avenues, Cincinnati, Ohio 45229, US1 Presented, in part, at the FASEB Meeting, 1989. (Poisner, R., Thrailkill, K., Poisner,A.M. and Handwerger, S. (1990) Evidence for cyclic-AMP and protein kinaseC as mediators ofprorenin release from human detidual cells. FASEBJournal, 4, A962.) Paper accepted 11.2.1991 SUMMARY The possible roles of cyclic AMP and protein kinase C in the release of renin from human decidual cells were investigated by examining renin releasefrom monolayers of decidual cells exposed for 72 h to agents that increase intracellular HP or activate protein kinase C. Dibuty yl LAMP (I O-l 000 PM caused a dose-dependent stimu- lation of renin release ajer a 24-h exposure. Maximal stimulation, 410 per cent greater than that of control cells, occurred at 72 h, and 98per cent of the renin released into the medium was in the form ofprorenin. Forskolin (l&l000 ~.L+I) and cholera toxin (CT 20-1000 ng/ml), both of which stimulate adenyl cyclase, also stimulated prorenin release. Phorbol myristate acetate (PMA), an activator ofprotein kinase C, had little efect on basalprorenin release at 100 nM butpotentiated the stimulation of prorenin release by a4MP and CT The eflects on prorenin release were paralleled by stimulation of active renin release. The results of this study therefore implicate CAMP and protein kinase C in the regulation of prorenin release from decidual cells and suggest that prorenin release from the decidua and other tissues is regulated by the same second messengers. INTRODUCTION Both human chorionic cytotrophoblast cells (Poisner, Wood and Poisner, 1982) and human decidual cells (Shaw et al, 1989) synthesize and secrete prorenin in vitro, suggesting a 01-13~4004/91/030263 + 05 $05.00/O 0 1991 Baillikre Tindall Ltd